The purpose of this four day meeting is to evaluate the current knowledge base and conceptual paradigms of obesity treatment and to suggest directions for future research and clinical practice. The field of obesity treatment is currently divided. At one extreme a group of scientists note that obesity is ever increasing in the United States as well as other nations and argue that obesity is a major independent risk factor for diabetes mellitus, cardiovascular disease, hypertension, hyperlipidemias, and early mortality. Consequently, they argue that obesity should be treated and have vigorously attempted to develop safe and effective treatments. At another extreme, there is a group of scientists who claim that the health hazards of obesity have been greatly overestimated and are often outweighed by iatrogenic effects of treatment. They question the ethics of applying conventional treatments and suggest alternatives based in promoting inter- and intra-individual acceptance of obesity. The one point of agreement is that, to date, while we have become successful in promoting weight loss, we are generally unsuccessful in promoting effective weight maintenance among obese persons. It can be argued that this confluence of positions implies that the current paradigm for conceptualizing, researching, and implementing obesity treatment has reached its limit and that new conceptualizations, research strategies, and treatment alternatives are needed. This international meeting will make that implication explicit. The main objective is for the meeting to be research generative rather than merely research reporting. Each speaker will be asked not only to summarize the state of our knowledge on a particular issue but more importantly to point out key gaps in that knowledge and important questions that have yet to be asked. Divergent views will be solicited from leading investigators in the field representing the disciplines of medicine, physiology, epidemiology, and psychology. The major topics to be addressed include: 1) defining appropriate goals; 2) maintaining weight losses; 3) predicting treatment outcome; 4) matching patients to treatments; 5) treatment implications of emerging findings in genetics and neuroendocrinology; 6) and methodological issues.